LiDAR-based place recognition.
Place recognition methods based on LiDAR scans can be split into two categories: handcrafted and learned descriptors. Among the first group, one of the most effective methods is ScanContext [1]}, which represents a 3D point cloud as a 2D image.
3D points above the ground plane level are converted to egocentric polar coordinates and projected to a 2D plane. This idea was extended in a couple of later works [2]}, [3]}.
